……………………..fision of the 3 palatal components initially prodices a flat , unarched roof of the mouth.the fusing lateral palatal shelves overlap the anterior palatal shelves as indicated later by the sloping pathways of the junctional incisive neurovascular canals that carry the previously formed incisive nerves and blood vesels.the site of junction the 3 palatal components is marked by the incisive papilla overlying the incisive canal.the line of fusion of the palatal shelves in adults is traced by the midpalatal suture .and on the surface by the raphae. This fusion seam is reducd in soft palate by the invasion of extraterritorial mesenchyme.

Palatopharyngeal incompetance due to muscle hypoplasis of uvula.paralysis following diphtheria due to action of toxin on nerve cells of medulla oblongata. Voice becoms nasal and fluid regurgiatesinto nose.palate is motionless and anaesthetic.other pathology of glossopharyngeal vagus accessory nerve or their nuclei in medulla odlongata causes palatal paralysis.

18.
SECONDARY PALATE
Starts at the 6 th week
Palatine shelves emerges laterally
from maxillary process
First descends vertically
downwards due to presence of tongue
Tongue drops, shelves ascends to a
horizontal position
Moves towards each other
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Fuses with each other

42.
OSSIFICATION OF PALATE
During the 8th week . . .
spreads backward to form
pyramidal process
downwards to form
tuberosity
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43.
OSSIFICATION OF PALATE
At the 9th week . . .
the two branches of the pyramidal process
are widely seperated for internal pterygoid plate
vertical plate is at 45°
later stages at right angles to the
horizontal plate
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68.
Drift . . .
drift is the movement of bone in space by virtue of
apposition on one side of a cortex or surface & resorption
on the other
palatal drift - classic example
nasal floor – resorptive &
roof of mouth - depository
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70.
COUNTERPART PRINCIPLE
growth of any given facial or cranial part
relates specifically to other structural &
geometric counterparts
if each regional part & its counterpart enlarge
to the same extent , balanced growth results
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102.
Concluding . . .
“If the rate of growth of the first month
of embryonic life were to be maintained
until adulthood, the resultant individual
would be 1,28,350 to the 1,100 power of
light years in length.”
-Robert Bean
( Anatomist)
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